1. Field of the Invention
This invention relates to programmable sequence controllers and to improved power-down, power-up circuitry for any data processing device.
2. Description of the Prior Art
A number of prior art patents disclose sequence controllers or mechanical drums for providing sequence control capability. A list of prior art is set forth below in Table 1. A majority of these references are directed to mechanical sequence drums of which U.S. Pat. No. 3,307,382, Hacker et al, appears to be the most relevant. This reference discloses a random access drum having binary coding for moving drum 11 to desired positions. The sequence of operations on drum 11 may be completely random, as specified by the operator, and is thus unlike most of the other prior art references. In short, this reference discloses an electro-mechanical random access means for controlling and moving an electro-mechanical programmer to control the sequence of cycles actuated by the programmer independently of the sequence of arrangement on the programmer. This reference, however, does not disclose an electronic emulation of mechanical sequence drums nor the capability of these simulated sequence drums to communicate with each other by internal memory bits; and thus become part of the overall control program. Branching capability
TABLE 1 ______________________________________ PRIOR ART REFERENCES Year Patent No. Inventor Issued ______________________________________ U.S.2,922,900 Gieringer 1960 3,008,059 Gorsuch et al 1961 3,189,697 Holzer 1965 3,194,902 Bauer 1965 3,204,087 Millis, Jr. 1965 3,215,791 Fontaine 1965 3,215,999 Dawson 1965 3,234,410 Sherman 1966 3,253,108 Mumma 1966 3,274,348 Blomquist et al 1966 3,307,382 Hacker et al 1967 3,331,929 Holtkamp 1967 3,413,425 Lovegrove 1968 3,477,258 Walker et al 1969 3,538,284 Alexander et al 1970 3,566,051 Hulterstrum et al 1971 3,566,364 Hauck 1971 3,586,918 Roland 1971 3,586,937 Holzer 1971 3,600,602 Yartz 1971 3,663,938 Baer 1972 3,717,730 Utter 1973 3,725,618 Voland et al 1973 3,735,063 Stillbert 1973 3,755,695 Krick et al 1973 3,809,831 Godwin et al 1974 3,819,886 Homan et al 1974 3,846,676 Ryczek 1974 3,864,611 Chang 1975 3,886,378 Morgan 1975 3,937,981 Nystuen et al 1976 3,264,397 Glickman et al 1966 3,382,489 VanBosse 1968 3,260,998 Fluegel 1966 3,142,820 Daniels 1964 3,752,966 Foy, Jr. et al 1973 3,665,399 Zehr et al 1972 3,760,167 Schrimshaw 1973 3,201,572 Yetter 1965 3,467,947 Rees 1969 3,459,925 Goosey et al 1969 2,877,398 Gimpel et al 1959 3,092,819 Cochinal 1963 3,039,687 Chope 1962 U.K.1,126,891 Jensen 1968 ______________________________________
is also not disclosed or suggested in this reference. Furthermore, the present invention is distinguished from Hacker et al by incorporating a clock-calendar capable of use in defining exit conditions upon which the controller leaves a currently scanned line to another specified drum line.
U.S. Pat. No. 3,204,087, Millis, Jr., discloses a general purpose parallel sequencing computer which utilizes a magnetic memory drum 23. The system provides for a generalized sequencing technique which possesses coding flexibility and is able to sequence a large number of actuators in a parallel relationship to each other, or in any mixture of serial and parallel relationships. The sequence technique employs a rotating magnetic memory drum, a series of output actuators to be controlled by the system, and a mechanical commutator driven by the drum which effectively interconnects to computer with actuators. The memory drum includes a working, a transfer, and a short re-circulating channel, all divided or programmed by several associated permanent channels, into a series of equally lengthened sections. The working channel holds the present or operating information of all sections, while the transfer channel carries advance information relating to the next actuator control cycle for each section. This reference however does not disclose or suggest multiple drum emulation by a single controller nor the communication from one drum to any other drum through the use of internal memory bits. Furthermore, a programming language of simple, user oriented format is neither disclosed nor suggest by Millis or any of the other cited prior art references. Furthermore, the power-down, power-up circuitry between the power supply and the remaining portions of the controller is neither disclosed nor suggested by this or any of the cited prior art references.
Lastly, U.K. Patent No. 1,126,891 discloses a sequence controller for a working machine. This controller has auxiliary switch means provided for rendering ineffectual the conditioning of the sequence control to provide a command signal for the next normal program stage. It also includes means for deriving at least one alternative command signal deviating from the normal program. This reference does not disclose multiple simulated drums nor their communication with each other. Furthermore, this reference does not disclose a simple user-oriented program language nor a clock-calendar capable of use as forming a part or all of an exit condition within any selected drum line.